Looking for a randomized unfair coin-flipping like application

[darktemplar]

Ok, I'm looking for some sort of internet based (preferably) application that works kind of like a random coin generator, but different, like instead of the coin being 50%, you can change how fair the coin is like say change the probability of heads to 82% and tails to 38%. I only want two outcomes, success or failure sort of thing, so something like a d20 with 20 outcomes is not what I'm looking for.

I've been looking for something like this for awhile now, but I just don't really know what to call it to find something like it. Any suggestions or links would be awesome, Thanks!

 

[Hefemeister]

For a quick result I would use a excel random number generator that returns a value between 0 and 1. =rand()

transform the numbers such that all values less than or equal to .82 is a 0 and all values greater than .82 is 1

You could have a more elegant solution using the inverse cdf of a binomial distribution but the above method should work fine for your purposes.

 

[darktemplar]

transform the numbers such that all values less than or equal to .82 is a 0 and all values greater than .82 is 1

How exactly would you do that? I'm not all that familiar with excel.

Thanks : D

 

[Hefemeister]

in a1 place the formula: =rand()
this will return a random number between 0 and 1.

in b2 place the formula: =IF(A1<=0.82,"0","1")
this will convert it to 1 or 0.

You could put any text you want in place of the 0 and 1 for example "true","false" which would return true for less than or equal to .82 and false for greater than .82

You could then copy the formulas down as many rows as trials you wish to run.
As n (number of trials) gets larger the average will come closer and closer to the actual probability of occurrence.

 

[darktemplar]

Ok, thank you very much!